Organic Does Not Mean Natural

What students typically write

“Organic chemistry is about natural substances.” Or: “Organic compounds are healthier because they are natural.” Or: “Organic food is part of organic chemistry.”

Students bring the supermarket definition of “organic” into the chemistry classroom. In everyday language, “organic” means grown without synthetic chemicals. In chemistry, it means something entirely different.

Why it is wrong

In chemistry, “organic” is defined by chemical composition, not by origin or health properties:

Organic compounds are compounds containing carbon, usually bonded to hydrogen, and often to oxygen, nitrogen, or halogens. They include alkanes, alkenes, alcohols, carboxylic acids, polymers, and many more families.

Inorganic compounds are everything else: metals, metal oxides, salts, water, carbon dioxide (CO2 and carbonates are traditionally classified as inorganic despite containing carbon).

The word “organic” in chemistry has historical roots: early chemists believed carbon compounds could only come from living organisms. That idea was disproved in 1828 when Friedrich Wohler synthesised urea (an organic compound) from inorganic starting materials. Today, organic chemistry is simply the chemistry of carbon compounds, regardless of source.

Many organic compounds are entirely synthetic: polyethene comes from an oil refinery, not from a plant. PVC, nylon, paracetamol, and food colourings are all organic compounds made in factories. Meanwhile, diamond (pure carbon) and marble (calcium carbonate) are natural but inorganic.

What the mark scheme actually wants

A typical question: “What is meant by organic chemistry?” [1]

Marking point:

1. The study of carbon compounds / compounds containing carbon and hydrogen (1 mark)

No mark for “the study of natural substances” or anything related to food labelling.

Worked example: wrong vs right

Question: Ethanol (C2H5OH) is an organic compound. Explain what is meant by the term organic in this context. [1]

Wrong answer: “Organic means ethanol is a natural substance and is not made with chemicals.” This scores 0/1. It confuses the everyday and chemical meanings.

Right answer: “Organic means ethanol is a carbon-containing compound / a compound based on carbon (1).” This scores 1/1.

How to avoid this mistake

When you see the word “organic” in a chemistry exam, mentally translate it to “carbon-based”. Forget the supermarket. Organic chemistry = carbon chemistry.

A quick test: does the compound contain carbon atoms bonded to other atoms (usually H, O, N, or halogens)? If yes, it is organic. If it is a metal compound, an ionic salt, or a simple gas like O2 or N2, it is inorganic. (Note: CO2 and carbonates are traditional exceptions classified as inorganic.)

For the full introduction to organic chemistry, see homologous series and alkanes.